Horrible experience. I have a long story to say but here is just what happened in brief..
We Talked to Simon who was the Manager of Colliers Wood's office to sell our property. We invited him to our home, talked to him honestly and told him that we plan to sell our property to buy a new house. And we told him that we put an offer for that property and we are short in time.
He promised to help us and be honest with us. Then he passed our case to Suzzane who is very rude, gready. After 3 visitors, she told us 2 of them put an offer which was less than we expected.
One of the offers was too low, Suzzane told me let's just pretend to them that you have accepted the offer, so we can have them and I will try to find another buyer. Meanwhile, she talked to the agency that was dealing with my buying property and told them we accepted the offer for selling our property and there shortly, we can forward for exchange contracts.
Anyway, at the end, I had to sell my flat for low price, get a huge mortgage and even borrow some money to buy the new property. I wish, I have never talked to Simon and Suzzane. For months Suzzane called me, that told me to trust her, but she just put me in lots of trouble.
My advice, never deal with them and if your sell and buy is a chain, never tell the agency about your buying plan.